Use of AgomiR and AntagomiR technologies to alter satellite cell proliferation in vitro, miRNA expression, and muscle fiber hypertrophy in intrauterine growth-restricted lambs

Introduction: microRNAs (miRNAs) are small non-coding RNAs that work at the posttranscriptional level to repress gene expression. Several miRNAs are preferentially expressed in skeletal muscle and participate in myogenesis. This research was conducted to alter endogenous miRNA expression in skeletal muscle to promote muscle hypertrophy. Methods: Two experiments were conducted using mimic/agomiR or antagomir technologies to alter miRNA expression and examine changes in myoblast proliferation in vitro (experiment 1) and muscle hypertrophy in vivo (experiment 2). In vitro experiments found that antagomiR-22-3p and mimic-127 increased myoblast proliferation compared to other miRNA treatments or controls. These miRNA treatments, antagomiR-22-3p (ANT22) and agomiR-127 (AGO127), were then used for intramuscular injections in longissimus muscle. Results and discussion: The use of antagomiR or mimic/agomiR treatments down-regulated or up-regulated, respectively, miRNA expression for that miRNA of interest. Expression of predicted target KIF3B mRNA for miR-127 was up-regulated and ACVR2a mRNA was up-regulated for miR-22-3p. ANT22 injection also up-regulated the major regulator of protein synthesis (mTOR). Proteomic analyses identified 11 proteins for AGO127 and 9 proteins for ANT22 that were differentially expressed. Muscle fiber type and cross-sectional area were altered for ANT22 treatments to transition fibers to a more oxidative state. The use of agomiR and antagomir technologies allows us to alter miRNA expression in vitro and in vivo to enhance myoblast proliferation and alter muscle fiber hypertrophy in IUGR lambs during early postnatal growth.

Laryngeal ultrasound to assess vocal fold paralysis in children

The purpose of this study was to assess the practicality and validity of laryngeal ultrasound to establish vocal fold movement in children with suspected vocal fold palsy. Fifty-five consecutive patients (age range three days to 12 years) with suspected vocal fold palsy underwent both laryngoscopy and laryngeal ultrasound. Ultrasonographic findings correlated with endoscopic findings in 81.2 per cent of cases. This, however, rose to a concordance rate of 89.5 per cent in patients aged over 12 months. Laryngeal ultrasound is well-tolerated, safe and non-invasive and the authors feel that it is a useful adjunct to endoscopy in the diagnosis of vocal fold palsy.

The effectiveness of guidelines in reducing inappropriate CT scans of the paranasal sinuses

An effective system for scoring pathological changes on CT scans of the paranasal sinuses has been developed by Lund & Mackay. We have performed an audit using 100 outpatients with nasal symptoms and found that adherence to guidelines prior to ordering CT scans of the paranasal sinuses correlates with an increased average Lund & Mackay score. Using these guidelines has also reduced the number of inappropriate CT scan requests.

Bilateral congenital cholesteatoma in branchio-oto-renal syndrome

Branchio-oto-renal syndrome is a rare autosomal dominant condition characterized by hearing loss, branchial arch abnormalities and renal tract malformations. We present the first reported case of branchio-oto-renal syndrome associated with bilateral congenital cholesteatoma and ossicular chain abnormalities. The pathogenesis of this syndrome is described and the literature is reviewed.

Myxoid chondrosarcoma of the external auditory meatus

Extraskeletal myxoid chondrosarcoma presenting in the head and neck is extremely rare. Histological diagnosis is difficult and requires close co-operation between clinician, radiologist and pathologist. The tumour has a good prognosis in comparison to myxoid chondrosarcoma of the bone but surgical resection may be difficult due to its gelatinous nature. We present a case of extraskeletal myxoid chondrosarcoma originating in the external auditory meatus of a 42-year-old man. This is the first report of this tumour in this site.

Rapidly invading sebaceous carcinoma of the external auditory canal

A very rare case of a sebaceous carcinoma of the external auditory canal with basal cell differentiation is presented. Fewer than 400 cases affecting any part of the body have so far been reported and of that only seven cases have been known to involve the external auditory canal. The clinical features, pathology and treatment are described and the relevant literature has been reviewed.

Pyoderma gangrenosum producing saddle nose deformity

Pyoderma gangrenosum affecting the nose is rare and this may lead to diagnostic confusion because of the large differential diagnosis. As diagnosis is made, largely, on the basis of exclusion the treatment of pyoderma gangrenosum may be unduly delayed. The condition is often disfiguring, particularly following inappropriate surgical intervention, and early diagnosis is therefore important. We present a case of pyoderma gangrenosum managed initially in the community with minor surgery and resulting in the rare complication of saddle nose deformity.

Mycotic aneurysm of the external carotid artery

Mycotic aneurysms of the extracranial carotid arteries are extremely rare. A case is reported of a false aneurysm of the left external carotid artery. This developed secondary to cervical lymphadenitis which did not settle with high dose antibiotic therapy. The diagnosis was made on investigation with carotid doppler ultrasound and confirmed with computerized tomography. Digital subtraction angiography was performed to highlight the vascular anatomy. In addition percutaneous balloon catheter control of blood flow in the external carotid artery was used as an adjunct to surgical management.